Chemical vapor deposition method

ABSTRACT

A chemical vapor deposition apparatus includes a deposition chamber defined at least in part by at least one of a chamber sidewall and a chamber base wall. A substrate holder is received within the chamber. At least one process chemical inlet to the deposition chamber is included. At least one of the chamber sidewall and chamber base wall includes a chamber surface having a plurality of purge gas inlets to the chamber therein. The purge gas inlets are separate from the at least one process chemical inlet. A purge gas inlet passageway is provided in fluid communication with the purge gas inlets. Further implementations, including deposition method implementations, are contemplated.

TECHNICAL FIELD

This invention relates to deposition methods and to chemical vapordeposition apparatus.

BACKGROUND OF THE INVENTION

Semiconductor processing in the fabrication of integrated circuitrytypically includes the deposition of layers on semiconductor substrates.Exemplary processes include physical vapor deposition (PVD), andchemical vapor deposition (CVD) including atomic layer deposition (ALD).With typical ALD, successive mono-atomic layers are adsorbed to asubstrate and/or reacted with the outer layer on the substrate,typically by successive feeding of different precursors to the substratesurface.

Chemical and physical vapor depositions can be conducted within chambersor reactors which retain a single substrate upon a wafer holder orsusceptor. The chambers include internal walls which can undesirablyhave deposition product deposited thereupon in addition to thesubstrate. This is particularly problematic in ALD and other CVDprocesses, yet can also occur with PVD chambers. One existing method ofprotecting or preserving the internal chamber walls is to shield suchfrom the deposition material with one or more removable liners. Theseliners might be received immediately adjacent or against the internalchamber walls. Alternately, the liners might be displaced therefrom,thereby defining an appreciably reduced volume chamber, or subchamber,within which the substrate is received for deposition. One advantage ofusing liners is that they can be periodically replaced with new orcleaned liners, thereby extending the life of the deposition chambers.Further and regardless, the spent liners can typically be removed andreplaced much more quickly than the time it would take to clean theinternal chamber walls at a given cleaning interval.

The invention was motivated in overcoming the above-described drawbacks,although it is in no way so limited. The invention is only limited bythe accompanying claims as literally worded without interpretative orother limiting reference to the specification or drawings, and inaccordance with the doctrine of equivalents.

SUMMARY

The invention includes deposition methods and chemical vapor depositionapparatus. In one implementation, a chemical vapor deposition apparatusincludes a deposition chamber defined at least in part by at least oneof a chamber sidewall and a chamber base wall. A substrate holder isreceived within the chamber. At least one process chemical inlet to thedeposition chamber is included. At least one of the chamber sidewall andchamber base wall includes a chamber surface having a plurality of purgegas inlets to the chamber therein. The purge gas inlets are separatefrom the at least one process chemical inlet. A purge gas inletpassageway is provided in fluid communication with the purge gas inlets.In one implementation, a chemical vapor deposition apparatus includes achamber defined at least in part by chamber walls. A chamber linerapparatus is included which forms a deposition subchamber within thechamber. A substrate holder is provided within the depositionsubchamber. The chamber liner apparatus includes a subchamber surfacehaving a plurality of purge gas inlets to the chamber therein. A purgegas inlet passageway is in fluid communication with the purge gasinlets.

In one implementation, a deposition method includes positioning asubstrate within a deposition chamber defined at least in part bychamber walls. At least one of the chamber walls includes a chambersurface having a plurality of purge gas inlets to the chamber therein. Aprocess gas is provided over the substrate effective to deposit materialonto the substrate. During the providing, purge gas is emitted to thedeposition chamber from the purge gas inlets effective to form an inertgas curtain over the chamber surface. In one implementation, adeposition method includes positioning a substrate within a depositionchamber defined at least in part by chamber walls. The depositionchamber has a component received therein internally of the chamberwalls. The component has a surface exposed to the chamber. The surfacehas a plurality of purge gas inlets to the chamber therein. A processgas is provided over the substrate effective to deposit material ontothe substrate. During the providing, purge gas is emitted to thedeposition chamber from the purge gas inlets effective to form an inertgas curtain over the component surface within the deposition chamber.

Further implementations are contemplated.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

FIG. 1 is a diagrammatic sectional view of a chemical vapor depositionapparatus in accordance with an aspect of the invention.

FIG. 2 is an enlarged sectional view of a portion of a chemical vapordeposition apparatus in accordance with an aspect of the invention

FIG. 3 is an enlarged sectional view of a portion of an alternateembodiment chemical vapor deposition apparatus in accordance with anaspect of the invention.

FIG. 4 is an enlarged sectional view of a portion of another alternateembodiment chemical vapor deposition apparatus in accordance with anaspect of the invention.

FIG. 5 is a diagrammatic sectional view of an alternate chemical vapordeposition apparatus in accordance with an aspect of the invention.

FIG. 6 is a diagrammatic sectional view of another alternate chemicalvapor deposition apparatus in accordance with an aspect of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This disclosure of the invention is submitted in furtherance of theconstitutional purposes of the U.S. Patent Laws “to promote the progressof science and useful arts” (Article 1, Section 8).

Referring to FIG. 1, an exemplary embodiment chemical vapor depositionapparatus in accordance with an aspect of the invention is indicatedgenerally with reference numeral 10. Such includes a chamber 15 definedat least in part by chamber walls 12, 14 and 16. Wall or walls 12comprise a chamber sidewall, wall or walls 14 comprise a chamber basewall, and wall or walls 16 comprise a chamber top wall. Chamber 15includes at least one process chemical inlet 18 thereto, and an outlet20 feeding therefrom. Outlet 20 feeds to a foreline 22 for connectionwith a vacuum pump (not shown). A suitable substrate holder 24 isprovided within chamber 15. Such includes some suitable supportstructure 26, and is illustrated as receiving a substrate 25, preferablya semiconductor substrate, thereatop. In the context of this document,the term “semiconductor substrate” or “semiconductive substrate” isdefined to mean any construction comprising semiconductive material,including, but not limited to, bulk semiconductive materials such as asemiconductive wafer (either alone or in assemblies comprising othermaterials thereon), and semiconductive material layers (either alone orin assemblies comprising other materials). The term “substrate” refersto any supporting structure, including, but not limited to, thesemiconductive substrates described above. Process gas inlet 18 isdiagrammatically shown as feeding to a showerhead 27 associated with alid of the apparatus for providing one or more process gasses tosubstrate 25 for deposition of a material thereon.

Chamber sidewalls 12 and chamber base walls 14 are depicted as havingchamber surfaces having a plurality of purge gas inlets 28 to thechamber formed therein. The depicted purge gas inlets are separate ordifferent from process gas inlet 18. Further in the depicted preferredembodiment, a plenum chamber 30 is formed behind walls 12, 14 and is fedby a purge gas inlet passageway 32, which is thereby in fluidcommunication with purge gas inlets 28. In preferred implementations,walls 12, 14 are constructed of highly porous materials, such assintered metal particles or fibers, low density teflon, or othersynthetic organic and/or inorganic materials, and by way of exampleonly. Material selection would ideally be based on intended processchemistries. Further by way of example only, walls 12, 14 might beconstructed to form a screen-like mesh, with pores/outlets 28 beingdefined by interstices thereof. The pore sizes of the material woulddepend on material characteristics and deposition processcharacteristics. Exemplary pore sizes include from tens of microns totens of Angstroms. Further by way of example only, walls 12, 14 mightcomprise an essentially solid, hard, planar wall surface having aplurality of openings 28 drilled or otherwise formed therein, such as isshown. In the FIG. 1 depicted preferred embodiment, the chamber surfacehaving the plurality of purge gas inlets 28 is essentially formed on andconstitutes both the chamber sidewall and the chamber base wall. Furtherby way of example only, such purge gas inlets might alternately beincluded only on either the sidewall or base wall, and also contemplatesthe chamber surface as being only a portion or portions thereof.Further, purge gas inlets might also be provided on a top wall ofchamber 15, for example in manners described herein, and in accordancewith U.S. patent application Ser. No. 09/805,620 filed on Mar. 13, 2001,entitled “Chemical Vapor Deposition Apparatus and Deposition Methods”,listing Craig M. Carpenter and Ross S. Dando as inventors, and which ishereby incorporated by reference.

In one implementation, and as depicted, the purge gas inlets aresubstantially uniformly distributed over the chamber surface over whichsuch are received. Further and/or additionally, purge gas inlets 28might all be of substantially constant size, or of at least two inletsizes. In one preferred embodiment, at least some of purge gas inlets 28which are further from chamber outlet 20 are larger than at least someof the purge gas inlets 28 which are closer to chamber outlet 20. Suchprovides one manner by which, if desired, a greater volumetric flow ofpurge gas can be provided proximate the respective wall surfaces furtherfrom chamber outlet 20 than closer thereto. A purge gas outletpassageway 36 is depicted as extending from purge gas inlet passageway32, 30 to foreline 22, thereby by-passing the plurality of purge gasinlets 28. Appropriate valving (not depicted) might, of course, beassociated with passageway 36 or any other of the depictedpassageways/inlets/outlets. A purge gas outlet passageway might beincluded to assist in control of the flow rate and pressure withinplenum chamber 30 and, thereby, also from purge gas inlets 28.

By way of example only, FIGS. 2, 3 and 4 depict exemplary alternateembodiments of purge gas inlets 28. For example, FIG. 2 depicts anexemplary chamber wall 40 having a chamber surface 42 having a pluralityof purge gas inlets 28 a received therein. Such are depicted ascomprising openings extending from a purge gas inlet passageway 44within wall 40 and which would be exposed to a deposition chamber, forexample deposition chamber 15. Accordingly, the exemplary depicted purgegas inlets 28 a in such embodiment (and inlets 28 in the FIG. 1embodiment) are configured for discharging purge gas to the chamber in adirection which is substantially transverse, for example in a direction“A” to chamber surface 42. In the context of this document, “a directionsubstantially transverse” is defined to mean anything from perfectlyperpendicular (90°) to the chamber surface to, but not including, 45°from the chamber surface.

FIG. 3 depicts an exemplary alternate embodiment chamber wall 40 b. Likenumerals from the FIG. 2 described embodiment are utilized whereappropriate, with differences being indicated by the suffix “b” or withdifferent numerals. Purge gas inlets 28 b are depicted as beingconfigured for discharging purge gas to the chamber in a directionsubstantially along chamber surface 42 b. In the context of thisdocument, “substantially along” means from 45° to parallel with thechamber surface. In the depicted exemplary FIG. 3 embodiment, chambersurface 42 b is provided (or alternately considered, purge inlets 28 bare provided) with deflectors/diverters/ramps 43 angled at an exemplary40° from surface 42 b for achieving such purge gas discharging generallyin a direction “B”.

Further by way of example only, FIG. 4 depicts yet another embodimentconfiguration for purge gas inlets 28 c. Like numerals from the FIGS. 2and 3 described embodiments are utilized where appropriate, withdifferences being indicated with the suffix “c”, or with differentnumerals. In FIG. 4, deflectors 43 c are depicted as curving or rampingto extend a portion thereof essentially parallel along surface 42 c.

The invention also contemplates deposition methods utilizing theabove-described equipment, and utilizing other equipment. In otherwords, the apparatus aspects of the invention are independent of themethodical aspects, and the methodical aspects are independent of theapparatus aspects, except with respect to literal claim-recitedlanguage, and without limiting or other interpretive reference to thespecification and drawings. In accordance with an aspect of theinvention, one preferred deposition method positions a substrate withina deposition chamber defined, at least in part, by chamber walls suchas, by way of example only, substrate 25 positioned within chemicalvapor deposition apparatus 10. At least one of the chamber wallscomprises a chamber surface having a plurality of purge gas inlets tothe chamber. For example, any multiple set or subset of purge gas inlets28, in conjunction with the FIG. 1 described embodiment, depict such aplurality of purge gas inlets.

A process gas is provided over the substrate effective to depositmaterial onto the substrate. In the depicted exemplary FIG. 1embodiment, one or more process gasses could be provided via process gasinlet 18 to showerhead 27. During the providing of such a process gaseffective to deposit material onto the substrate, purge gas is emittedto the deposition chamber from purge gas inlets effective to form aninert gas curtain over the chamber surface having such plurality ofpurge gas inlets. Exemplary inert purge gases include noble gases andN₂. A preferred and desired, although non-limiting, goal of suchemitting is to restrict or perhaps completely prevent deposition productor effluent product from depositing upon the chamber surface or surfaceshaving such purge gas inlets associated therewith. In accordance withpreferred methodical aspects of the invention in forming an inert gascurtain, total inert purge gas flow from all inlets is ideally ratherlow, for example from 100 to 200 sccm in a six liter reactor, so as tonot adversely load or undesirably affect the sizing requirements of thevacuum pumping equipment.

In one preferred methodical aspect of the invention, the purge gas isemitted to the chamber in a direction substantially transverse to thechamber surface associated with the purge gas inlets and, in oneembodiment, is also effective to form the inert gas curtain to comprisesubstantially turbulent gas flow proximate the chamber surface. Inanother preferred embodiment, the purge gas emitting to the chamber isin a direction substantially along the chamber surface and, in oneembodiment, is additionally effective to form the inert gas curtain tocomprise substantially laminar gas flow proximate the chamber surface.In some operating regimes, viscous or turbulent flow may be desiredproximate the surface being protected, whereas in other regimes laminarflow might be desired.

In one embodiment, the purge gas emitting comprises emitting a greatervolume of purge gas from at least some purge gas inlets located furtherfrom the chamber outlet than from at least some purge gas inlets locatedcloser to the chamber outlet. Such might be accommodated by providinglarger outlets further from the chamber outlet than closer to thechamber outlet, and/or by providing greater flow and/or pressure to thepurge gas inlets which are located further/furthest from the chamberoutlet. In accordance with methodical aspects of the invention,preferred depositions include chemical vapor deposition, includingatomic layer deposition.

The above-described exemplary embodiments/implementations wereessentially in conjunction with chamber walls which effectively define amaximum internal volume within a deposition apparatus 10. FIG. 5 depictsan exemplary alternate chemical vapor deposition apparatus 10 a. Likenumerals from the FIG. 1 described embodiment are utilized whereappropriate, with differences being indicated with the suffix “a”, orwith different numerals. Chemical vapor deposition apparatus 10 aincludes a chamber liner apparatus 50 forming a deposition subchamber 17within chamber 15 a. Chamber liner apparatus 50 comprises subchambersurfaces 51 having a plurality of purge gas inlets 52 to the subchambertherein. By way of example only, purge gas inlets 52 might be configuredin any of the manners described above, including the depictions withrespect to inlets 28, 28 a, 28 b and 28 c described above. Further,liner apparatus 50 would ideally be configured or fabricated to be aneasily replaceable component of apparatus 10 a. By way of example only,the exemplary FIG. 5 embodiment depicts the various walls of linerapparatus 50 as comprising a retained intertwined, mesh-like materialwhich is fed by a plurality of purge gas inlet passageways 56 forproviding the desired purge gas thereto during deposition. Otherpreferred attributes of the FIGS. 1-4 depicted apparatus, and allmethods, as described above can be incorporated with chamber linerapparatus 50.

In accordance with some aspects and implementations of the invention,alternate exemplary embodiments are described with reference to FIG. 6.Like numerals from the first-described embodiments are utilized whereappropriate, with differences being indicated with the suffix “f”, orwith different numerals. FIG. 6 depicts a chemical vapor depositionapparatus 10 f comprising a deposition chamber 15 f which is at least inpart defined by chamber walls 12 f, 14 f and 16 f. Substrate holder 24 fcomprises support structure 26 f. Such includes a surface or surfaces 70exposed to chamber 15 f and which comprise(s) a plurality of purge gasinlets 75 to chamber 15 f. An exemplary purge gas inlet passageway 77 isshown in communication with support structure 26 f, and accordingly withpurge gas inlets 75. Such purge gas inlets might have any of theattributes described above with respect to the other describedembodiments. The FIG. 6 10 f depicted apparatus might be utilized inconjunction with purge gas to preclude, or at least reduce, theundesired deposition of material onto the depicted surface or surfacesof the substrate holder support structure.

Regardless, and in accordance with another methodical implementation ofthe invention, a deposition method comprises positioning a substratewithin a deposition chamber defined at least in part by chamber walls.The deposition chamber comprises a component received therein internallyof the chamber walls. By way of example only, substrate holder 24 f andits associated support structure 26 f is one exemplary such component.However, any other component is contemplated in accordance with thismethodical aspect of the invention. The component comprises a surface,exposed to the chamber, which has a plurality of purge gas inlets to thechamber therein. A process gas is provided over the substrate effectiveto deposit material onto the substrate. During providing of the processgas, purge gas is emitted to the deposition chamber from the purge gasinlets effective to form an inert gas curtain over the component surfacewithin the deposition chamber. A preferred effect is to prevent, or atleast reduce, undesired material from depositing onto such componentsurface. Any other attribute, as described above with respect to othermethodical aspects of the invention, is of course contemplated.

Control of the purge gas flow can be through a variety of methods, suchas an active feedback control loop based on a pressure sensors ported tothe purge gas channels and linked to mass flow controllers, needlevalves, EMCO digital valve-type flow control, line pressure regulatorsor other existing or yet-to-be developed methods.

In compliance with the statute, the invention has been described inlanguage more or less specific as to structural and methodical features.It is to be understood, however, that the invention is not limited tothe specific features shown and described, since the means hereindisclosed comprise preferred forms of putting the invention into effect.The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1-27. (Cancelled).
 28. A deposition method comprising: positioning asubstrate within a deposition chamber defined at least in part bychamber walls, at least one of the chamber walls comprising a chambersurface having a plurality of purge gas inlets to the chamber therein;providing a process gas over the substrate effective to deposit materialonto the substrate; and during the providing, emitting purge gas to thedeposition chamber from the purge gas inlets effective to form an inertgas curtain over the chamber surface.
 29. The method of claim 28comprising emitting the purge gas to the chamber in a directionsubstantially transverse to the chamber surface and effective to formthe inert gas curtain to comprise substantially turbulent gas flowproximate the chamber surface.
 30. The method of claim 28 comprisingemitting the purge gas to the chamber in a direction substantially alongthe chamber surface and effective to form the inert gas curtain tocomprise substantially laminar gas flow proximate the chamber surface.31. The method of claim 28 wherein the one chamber wall having theplurality of purge gas inlets is a sidewall.
 32. The method of claim 28wherein the one chamber wall having the plurality of purge gas inlets isa base wall.
 33. The method of claim 28 wherein the deposition chambercomprises a sidewall and a base wall, the plurality of purge gas inletsbeing received on both the sidewall and the base wall.
 34. The method ofclaim 28 wherein the deposition chamber includes an outlet therefrom,the emitting comprises emitting a greater volume of purge gas from atleast some purge gas inlets located further from the chamber outlet thanat least some purge gas inlets located closer to the chamber outlet. 35.The method of claim 28 wherein the chamber includes a chamber outlettherefrom, at least some of the purge gas inlets further from thechamber outlet being larger than at least some of the purge gas inletscloser to the chamber outlet, the emitting comprising emitting a greatervolume of purge gas from the at least some purge gas inlets locatedfurther from the chamber outlet than from the at least some purge gasinlets located closer to the chamber outlet.
 36. The method of claim 28wherein the chamber wall having the chamber surface comprises a surfaceof a chamber liner apparatus forming a deposition subchamber within thechamber.
 37. The method of claim 28 comprising chemical vapordeposition.
 38. The method of claim 37 comprising atomic layerdeposition.
 39. A deposition method comprising: positioning a substratewithin a deposition chamber defined at least in part by chamber walls,the deposition chamber comprising a component received thereininternally of the chamber walls, the component comprising a surfaceexposed to the chamber, the surface comprising a plurality of purge gasinlets to the chamber therein; providing a process gas over thesubstrate effective to deposit material onto the substrate; and duringthe providing, emitting purge gas to the deposition chamber from thepurge gas inlets effective to form an inert gas curtain over thecomponent surface within the deposition chamber.
 40. The method of claim39 wherein the component comprises a portion of a substrate supportreceived internally of the chamber walls.
 41. The method of claim 39comprising emitting the purge gas to the chamber in a directionsubstantially transverse to the surface and effective to form the inertgas curtain to comprise substantially turbulent gas flow proximate thesurface.
 42. The method of claim 39 comprising emitting the purge gas tothe chamber in a direction substantially along the surface and effectiveto form the inert gas curtain to comprise substantially laminar gas flowproximate the surface.
 43. The method of claim 39 wherein the depositionchamber includes an outlet therefrom, the emitting comprises emitting agreater volume of purge gas from at least some purge gas inlets locatedfurther from the chamber outlet than at least some purge gas inletslocated closer to the chamber outlet.
 44. The method of claim 39 whereinthe chamber includes a chamber outlet therefrom, at least some of thepurge gas inlets further from the chamber outlet being larger than atleast some of the purge gas inlets closer to the chamber outlet, theemitting comprising emitting a greater volume of purge gas from the atleast some purge gas inlets located further from the chamber outlet thanfrom the at least some purge gas inlets located closer to the chamberoutlet.
 45. The method of claim 39 comprising chemical vapor deposition.46. The method of claim 45 comprising atomic layer deposition.